More than three-quarters of bumblebee species across Europe may be threatened in the next few decades unless plans are in place to tackle the effects of climate change, according to researchers.
The scientists said around 32–76% of the European bumblebee species they studied are currently classified as “least concern” by the International Union for Conservation of Nature (IUCN), a global environmental organisation documenting the status of the natural world.
The models, published in the journal Nature, are estimates that represent the worst-case scenarios that would see European bumblebees lose up to 30% of their current habitat in the next 40–60 years, putting 75% of the species at risk.
For several decades, scientists have been sounding the alarm about the decline of pollinators, and bumblebees in particular— Dr Guillaume Ghisbain
Bumblebee species from Arctic and alpine environments may be at the verge of extinction in Europe, the researchers said, with an expected loss of at least 90% of their territory in the same period.
Dr Guillaume Ghisbain a conservation biologist at Free University of Brussels in Belgium, said he was “deeply saddened” by the findings.
He said: “For several decades, scientists have been sounding the alarm about the decline of pollinators, and bumblebees in particular.
“Population trends of the latter have been extensively studied in Europe in recent decades, and their decline has been pronounced in many different countries.
“Belgium, for example, is a case in point, where a fifth of the species that were once present in the country have completely disappeared.”
We closely observe nature, communicate with colleagues around the world studying pollinators, and we all arrive at convergent conclusions – pollinators are declining, often more severely than previously thought— Dr Guillaume Ghisbain
Dr Ghisbain added: “I believe this is the case today for many conservation biologists: we closely observe nature, communicate with colleagues around the world studying pollinators, and we all arrive at convergent conclusions – pollinators are declining, often more severely than previously thought.”
The bumblebee is considered to be critical to crop pollination in the cold and temperate regions of the northern hemisphere.
With their natural habitats being destroyed, alongside increase in global temperatures, the researchers said understanding the impact of these changes on insect populations is important for coming up with conservation plans.
For the study, Dr Ghisbain and his team used observational data from 1901–1970 and 2000–2014 to develop their models, with projections are made up to 2080.
These models suggest that Scandinavia – where the climate is much cooler – may potentially become refuges for displaced or threatened species but Dr Ghisbain said there are conditions to that.
He said: “For this region to effectively host a diverse bumblebee community in the future, it will be essential to ensure that it remains free from numerous factors of decline that were not accounted for in our models.
“These factors include heatwaves, droughts, the extensive use of pesticides, among others.
“Another significant risk is that if many species converge in the same area, they could geographically concentrate their parasites, potentially impacting their communities.”
Dr Ghisbain also said there was no guarantee that bumblebees will indeed be able to migrate to Scandinavia from other parts of Europe.
He said: “This is why we should not take Scandinavia or any other potential refugia (habitats) for granted: the survival of bumblebees will ultimately depend on how we protect our natural habitats and climates at a large scale.”
